1. Field of the Invention
The present general inventive concept relates to an image forming apparatus. More particularly, the present general inventive concept relates to a cleaning apparatus having an improved structure to remove toner remaining on a transfer medium, and a transfer unit and an image forming apparatus including the same.
2. Description of the Related Art
Generally, an image forming apparatus in which an electrophotographic process is used, for example, a laser beam printer or a copier, develops an electrostatic latent image formed on a photosensitive medium using toner, and transfers the developed image onto a printing medium through a transfer unit to output a desired image.
The transfer unit includes a belt which is installed between at least two rollers and rotates following a regular cycle. The belt is provided so as to be in contact with the outer circumference of at least one photosensitive medium, and the image developed on the photosensitive medium is thus transferred to the belt.
The belt cleaning apparatus removes unnecessary toner remaining on the belt after an image primarily transferred to the belt is secondarily transferred onto paper, and accordingly keeps the belt in a clear state.
FIG. 1 is a view schematically showing a general belt cleaning apparatus. As illustrated in FIG. 1, a belt 1 is wound around a roller 2 and rotates following a regular cycle. Additionally, a leading end of a cleaning blade 3, which is mounted on a blade bracket 4, is in contact with the belt 1 wound around the roller 2. Accordingly, the toner remaining on the belt 1 is removed by the cleaning blade 3.
The blade bracket 4 is constituted to move to a first position and a second position by a cam (not illustrated) so that the cleaning blade 3 can be selectively in contact with the belt 1. The first position is a position in which the cleaning blade 3 is in contact with the belt 1, as illustrated in FIG. 1, and the second position (not illustrated) is a position in which the cleaning blade 3 is separated from the belt 1.
When toner image formed on the photosensitive medium is transferred to the belt 1, or toner image of the belt 1 is transferred onto the printing medium, the cleaning blade 3 may be separated from the belt 1 via the blade bracket 4 being placed in the second position. Additionally, when the transferring process is completed, the blade bracket 4 may be moved to the first position by the cam, and thus the cleaning blade 3 is placed in contact with the belt 1 to remove non-transferred toner thereon.
However, in the typical belt cleaning apparatus as described above, since the cam enables the cleaning blade 3 be in contact with or separated from the belt 1 by applying a relatively large force, the leading end of the cleaning blade 3 may be damaged or the cleaning blade 3 may be bent. If the cleaning blade 3 is damaged or bent, it can no longer remove toner remaining on the belt. In this situation, it would be required to replace or repair the cleaning blade.